1. Field of the Invention
The present invention relates to an optical writing and reading apparatus, and more particularly to an optical writing and reading apparatus which is adapted to enable a position of a spindle motor in a tangential direction to be easily controlled in a case of assembly of the spindle motor, thereby facilitating adjustment of phase differences of an optical disk.
2. Description of the Prior Art
In general, an optical writing and reading apparatus used to write data on a disk and/or read data from a disk by using an optical system.
In such an optical writing and reading apparatus, an optical disk is seated on a turntable by a disk loading device, and is rotated at a certain rotational speed by a spindle motor. During rotation of a disk, the optical pickup irradiates laser beams on the disk to write data on the disk or read data from the disk while radially moving on the disk by a driving motor and gears.
FIG. 1 shows a conventional deck base assembly of an optical writing and reading apparatus. As shown in the drawing, a deck base 1 is formed with an opening 1a at its center, and is provided at its side with a spindle motor 2, which is mounted thereon via a bracket 4. A turntable 3, on which an optical disk xe2x80x9cDxe2x80x9d is seated, is rotatably coupled to a shaft of the spindle motor 2 and supported thereby.
A primary shaft 6 and a secondary shaft 6xe2x80x2 are extended parallel to and along both sides of the opening 1a, and the opposite ends of the primary and secondary shafts 6 and 6xe2x80x2 are supported on the deck base 1 by support members 7 which are fixed to the deck base 1 to be adjusted in tilt.
An optical pickup including an object-glass 5a is mounted on the primary and secondary shafts 6 and 6xe2x80x2, and moved along the primary and secondary shafts 6 and 6xe2x80x2 by the transmission gears 8.
FIG. 2 shows a spindle motor mounted on a deck base. As shown in the drawing, the spindle motor 2 is integrally provided at its bottom with a bracket 4 fixed thereto, and the bracket 4 is joined to an upper surface of a deck base 1 by screws xe2x80x9cBxe2x80x9d, thereby fixing the spindle motor 2 to the deck base 1.
More specifically, the deck base 1 is formed with a central hole 1b over which the spindle motor 2 is placed, and is formed around the central hole with fastening holes 1c through which the screws xe2x80x9cBxe2x80x9d are screwed. The bracket 4 is formed with a center reference hole 4a at a position corresponding to the central hole 1b, and is formed around the reference hole 4a with assembly holes 4b corresponding to the fastening holes 1c and with specific spacing.
However, such a conventional optical writing and reading apparatus has disadvantages in that the center of an object-glass does not coincide with the center of a turntable but deviates from the center of the turntable because of deformation of components or manufacturing tolerance, thereby deteriorating optical performance.
That is, when a spindle motor 2 is coupled to a deck base 1 or an optical pickup 5 is mounted on primary and secondary shafts 6 and 6xe2x80x2, and when tilt of a deck base 1 is adjusted using a separate tilt adjusting device, the center of an object-glass 5a does not coincide with the center of a turntable 3 but deviates from the center of the turntable 3 because of deformation of components or manufacturing tolerance, thereby causing operational errors and thus deteriorating reliability of products.
Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide an optical writing and reading apparatus which is capable of adjusting a fixing position of a turntable so as to overcome phase differences between an object-glass and the turntable, which may occur during assembly.
In order to accomplish the above object, the present invention provides an optical writing and reading apparatus comprising: a deck base having an opening at its center, on which an optical pickup including an object-glass is mounted to be moved along both sides of the opening, and which is formed adjacent to the opening with a center hole elongated in a direction perpendicular to a moving direction of the optical pickup, and is formed around the center hole with a plurality of fastening holes into which screws are screwed; and a spindle motor having a turntable at its shaft and having an integral bracket at its bottom surface, the bracket being formed at its center with a center reference hole and formed around the center reference hole with assembling holes elongated in a direction perpendicular to a moving direction of the optical pickup, the assembling holes being arranged at positions corresponding to the fastening holes of the deck base.